Automatic pressure-controlled switch



Aug. 6, 1929. v. TANNEHILL 1,723,635

AUTOMATIC PRESSURE CONTROLLED SWITCE Filed May 16, 1927 2 Sheets-Sheet 1 Aug. 6, 1929. v. L. TANNEHILL AUTOMATIC PRESSURE CONTROLLED SWITCH Filed May 16, 1927 2 Sheets-Sheet 2 a J 3 Q Wm.

Patented Aug. 6, 19,29.

UNITED STATES 1,723,635 PATENT OFFICE...

VERNON I4. TANNEHILI JQF FORT WAYNE. INDIANA, ASSIGNOR TO FORT WAYNE ENGINEERING & MFG. (30., 0F FORT WAYNE, INDIANA.

.AUTOMATIC' BRESSURE-CONTROLLED SWITCH.

I Application filed May 16,

This invention relates to automatic pressure controlled switches.

In pressure controlled switches, difiiculty has been experienced in securing a proper range of adjustment and also in attaining an accurate controlof the point or the pressure at which the switch will operate- Objects of this invention are to avoid the difliculties noted above and to provide a switch controlled by pressure responsive means, which is so constructed that it has a wide range of adjustment and may be accurately set atthe desired point with assurance that it will continuously function in a .reliable manner.

Further objects are to provide a switch of the above type in which a sudden make and break is secured in a wholly automatic manne'r' and by relatively simple mechanism,

having a small-number of parts, Furtherobjects are to provide a switch 1n which the parts are freely. accessible so that they may be inspected or renewed as required and in whlch all of the parts are of rugged'and sturdy formation.-

An embodiment of the invention is shown in the accompanying drawings in which:

Figure 1 is a side elevation of the device with the cover in section;

Figure 2 is a sectional view approximately centrally of the device;

Figure 3 is a sectional view on the line 33 of Figure 1;

Figure 4 is a sectional view on the line 44 of Figure 1. I

Referring to the drawings, it will be seen that the switch comprises a base portion 1 which is provided with a chamber 2 and with a screw threaded cap 3. Between the cap 3 of the base and the body portion 1, a diaphragm 4 is clamped. Preferably, gaskets 5 are' provided, as shown in Figure 2, to provide cutting at the edges of the. diaphragm.

The chamber 2 communicates with a pipe 6 leading tothe desired point. The ca 3 is provided with a cylindrical recess 7 wit in which the enlarged portion 8 of a plunger is slidably guided, said plunger continuing upwardly to provide a conical bearing por- .tion 9. i The base is also provided with a pair of uprights 10 which are referably integral with the cap portion 3 of the base and these uprights are joined at their upper ends to provide an overhanging flange or lip 11 .screw 27 is threaded through the overhangof the lever is connected to the tension spring or control spring 16, the other end of such spring being received in an aperture in the adjusting bolt or screw 12. The other end of the lever 14 is bifurcated and carries a. grooved roller 17.

The uprights 10 have pivotally mounted between them a curved lever 18 which is provided with a downwardly extending arm 19 and with an outwardly extending portion. The outwardly extending portion carries a pivotally mounted or swingingly mounted link 20 whose lower end is provided with a cam portion 21. This cam portion 21, it is to be noted from Figure 2, is formed by two converging faces 22 and 23 which to gether form a pcak The link 20 is urged inwardly by means of the spring 24. The spring 24 is preferably anchored to the transverse portion 25 -(see Figure 2) which joins upwardly extending arms 26 projecting from the members 13. An adjusting ing upper portion 11 and limits the outward throw of the downwardly extending portion 19 of the lever 18. I

The downwardly extending portion 19 of the lever carries a cross head 28 preferably formed of insulating material and held between a pair of lips integral with the lever. It is also desirable to secure the cross head in place by means of the screw 29, as shown in Figure 2. This cross head carries a pair of guiding channel-like clips 30 between which sets of spring fingers or movable contacts 31 are positioned. These spring fingers or movable contacts are urged inwardly by means of spring 82 loosely surrounding bolts 100 It is to be noted from Figure 2, that the no? blocks in turn carry the roller 17 bears against the cam faces 23 or 22, depending upon the position of the parts.

Preferably, the link 20 isthin at its lower end and fits within the groove of the roller. As it is urged inwardly by the spring 24 its cam face produces an upward thrustwhen the parts are in the position shown in Figure 2, and consequently, the switch is in 7 closed position and remains so, irrespective of a certain limited motion of the lever 4. However, when the pressure rises above the desired point the roller passes the peak of the cam 21 and thus the thrust upon the link 20 is reversed and is now downward.

This is transmitted to the lever 18 and, consequently, quickly snapsthe switch open.

- Upon reverse motion of the lever 4, as for instance, when the pressure falls, the link '20'exerts a -continuous downward pull until the roller passes the peak of the cam 21 at which time an upward thrust is suddenly imparted to the link 20, thus closing the switch.

The device has a wide range of adjustment and the exact pressure desired may be secured by adjusting the nut of the bolt 12 (see Figure 2). Further, inasmuch as the link 20 is relatively long and the rocking motion due to its cam portion is limited, it

is apparent that a substantially uniform up ward or downward pressure is exerted, due

to the cam action in conjunction with the spring, 24, Consequently, control of the point at w 1ch the switch will operate issecured by this construction.

It is to be noted also that although the switch has a quick make and break and is automatically controlled, that nevertheless it is of exeremely simple and rugged construction and may be cheaply produced. In addition tothese features,-the device is so made that all of the parts are'readily accessible when the casing 36 is removed. 1

Although the invention has been described in considerable detail, such description is intended as illustrative rather than limiting as the ,invention may be variously embodied and as the scope of such invention is to be determined as claimed.

I claim: v

1. An automatic switch comprising a body portion having a chamber formed therein, a.

pipe leading from said chamber, a diaa very accurate tion of said roller, a spring urging said linkv inwardly towards said roller, said second I lever having a downwardly extending arm, an insulating cross head carried by said arm, movable spring contact fingers carried by said cross head, an insulating member carried by said uprights, and stationary contacts carried by'said insulating member and adapted "to cooperate with said spring fingers.

2. An automatic switch comprising a body portion having a chamber formed therein, a

pipe leading from said chamber, a diaphragm mounted transversely of said chamber, a movable plunger operated from said diaphragm, a pivoted lever mountedabove said plunger and contacting therewith, an adjustable spring urgingsaid lever into engagement with said plunger, s'aid lever having a grooved roller at its outer end, a pair of uprights carried by said body portion, a second lever pivotally mounted between said uprights, a 11111! suspended from one end of said second lever and having a wedge-shaped cam portion fitting'within the grooved portion of said roller, a spring urging said link inwardly towards .sai d roller, said sec- 0nd lever having a downwardly extending arm, an insulating cross head carried by said arm, movable spring contact fingers carried by said cross head, an insulating member carried by said uprights, and stationary contacts carried by said insulating member and adapted to cooperate with said spring fin gers, said uprights having an adjusting screw adjacent their upper portions for lim'-' lting the opening movement of said switch.

In testimony that I claim the foregoing I have hereunto set my hand at Fort Wayne,

in the county of Allen and Sta tent Indiana' VERNON TANNEHILL. 

